A Study of Vehicle Fuel Economy Improvement Potential by Optimization of the Cooling and Ancillary Systems of a Heavy Duty Engine

It is desired to optimize a spark ignition PFI (port fuel injected) engine for various regimes within the operating ranges of a vehicle. The goal of this work is to identify the set of technologies that complement each other and offer the optimum performance and fuel economy. For an ideal powertrain system, the engine should be optimized for best fuel economy during the typical drive cycles and best performance during high load acceleration. A typical PFI 1.8L four-cylinder engine is baselined at cycle representative speed/load points. The engine is supercharged and intercooled to later quantify the efficiency benefits from replacing a larger engine with a smaller boosted engine that offers similar performance. Then the effects of different operating regimes and the effect of different proposed technologies are studied. The fuel economy enablers considered include variable valve timing (VVT) and variable compression ratios (VCR). The effects of VVT was studied to see which valve event scenarios afford the best operating efficiency and fuel economy during part load operation. VVT can also be a source of performance improvement if implemented appropriately. VCR operation is studied to see if the efficiency gains from VCR are additive with VVT or if they overlap to some degree. Typically, the fuel efficiency potential of a production engine is limited by spark knock. The engine studied here uses the geometrical and virtual compression ratio reductions offered by the VVT and VCR systems to give knock limit relief and allows the knock-limited BMEP curve to be pushed up. The results showed that the fuel economy gain with the above mentioned technologies is somewhat additive throughout the typical driving cycle but is highly dependent on proper optimization of the many system variables.

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Fuel Economy Improvement of a Heavy-Duty Powertrain by Using Hardware-in-Loop Simulation and Calibration

Energies ◽

10.3390/en8099878 ◽

2015 ◽

Vol 8 (9) ◽

pp. 9878-9891 ◽

Cited By ~ 2

Author(s):

Bolan Liu ◽

Xiaowei Ai ◽

Pan Liu ◽

Chuang Zhang ◽

Xingqi Hu ◽

...

Keyword(s):

Fuel Economy ◽

Heavy Duty ◽

Fuel Economy Improvement ◽

Hardware In Loop ◽

Hardware In Loop Simulation

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Numerical analyses of a hydraulic hybrid powertrain system for a transit bus

Thermal Science ◽

10.2298/tsci190308172k ◽

2020 ◽

Vol 24 (1 Part A) ◽

pp. 159-170

Author(s):

Marko Kitanovic ◽

Slobodan Popovic ◽

Nenad Miljic ◽

Predrag Mrdja

Keyword(s):

Dynamic Programming ◽

Fuel Economy ◽

Model Parameters ◽

Hybrid Powertrain ◽

Hydraulic Hybrid ◽

Powertrain System ◽

Improvement Potential ◽

Fuel Economy Improvement ◽

Hydraulic Accumulator ◽

Transit Bus

A dynamic programming optimization algorithm has been applied on a transit bus model in MATLAB in order to assess the fuel economy improvement potential by implementing a hydraulic hybrid powertrain system. The numerical model parameters have been calibrated using experimental data obtained on a Belgrade?s public transport bus. This experiment also provided the representative driving cycle on which to conduct simulation analyses. Various functional parameters of a hydraulic hybrid system have been evaluated for obtaining the best possible fuel economy. Dynamic programming optimization runs have been completed for various hydraulic accumulator sizes, preload values and accumulator foam quantities. It has been shown that a fuel economy improvement of 28% can be achieved by implementing such a system.

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Estimation of GHG Emissions Reduction and Fuel Economy Improvement of Heavy-Duty Trucks by Using Side Skirt and Boat Tail

Journal of Climate Change Research ◽

10.15531/ksccr.2016.7.2.177 ◽

2016 ◽

Vol 7 (2) ◽

pp. 177

Author(s):

Chul-Haeng Her ◽

Byoeng-Gyu Yun ◽

Dae-Wook Kim

Keyword(s):

Fuel Economy ◽

Ghg Emissions ◽

Emissions Reduction ◽

Heavy Duty ◽

Fuel Economy Improvement

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Modeling of Compressed Air Hybrid Operation for a Heavy Duty Diesel Engine

ASME 2008 Internal Combustion Engine Division Spring Technical Conference ◽

10.1115/ices2008-1679 ◽

2008 ◽

Cited By ~ 1

Author(s):

Xiaoyong Wang ◽

Tsu-Chin Tsao ◽

Chun Tai ◽

Hyungsuk Kang ◽

Paul N. Blumberg

Keyword(s):

Diesel Engine ◽

Fuel Economy ◽

Internal Combustion Engines ◽

Compressed Air ◽

Valve Timing ◽

Heavy Duty ◽

Vehicle Simulation ◽

Heavy Duty Diesel Engine ◽

Fuel Economy Improvement ◽

Heavy Duty Diesel

Internal combustion engines can be modified to operate regenerative braking cycles by using compressed air power. This paper presents a particular air hybridization design from among many possible configurations. The engine cycles are enabled by a highly flexible engine valvetrain, which actuates engine valves to generate desired torque with optimal efficiency. A lumped parameter model is developed first to investigate the cylinder-tank mass and energy interaction based on thermodynamic relationships and engine piston kinematics. Special consideration is given to the engine valve timing and air flow. A high fidelity, detailed model using the commercially available GT-Power software is developed for a commercial 10.8 liter heavy-duty diesel engine with a 280 liter air tank in order to capture the effects of engine friction, heat transfer, gas dynamics, etc. The model is used to develop optimal valve timing for engine control. The established engine maps are incorporated into the ADVISOR vehicle simulation package to evaluate the potential fuel economy improvement for a refuse truck under a variety of driving cycles. Depending on the particular driving cycle, the simulation has shown a potential 4% – 18% fuel economy improvement over the truck equipped with the conventional baseline diesel engine.

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Modeling of Compressed Air Hybrid Operation for a Heavy Duty Diesel Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.3078788 ◽

2009 ◽

Vol 131 (5) ◽

Cited By ~ 4

Author(s):

Xiaoyong Wang ◽

Tsu-Chin Tsao ◽

Chun Tai ◽

Hyungsuk Kang ◽

Paul N. Blumberg

Keyword(s):

Diesel Engine ◽

Fuel Economy ◽

Second Law Of Thermodynamics ◽

Lumped Parameter Model ◽

Compressed Air ◽

Heavy Duty ◽

Vehicle Simulation ◽

Heavy Duty Diesel Engine ◽

Fuel Economy Improvement ◽

Heavy Duty Diesel

This paper presents the analysis and modeling of a 10.8 l heavy-duty diesel engine modified for operating compressed air hybrid engine cycles. A lumped parameter model is developed to first investigate the engine cylinder-air tank mass and energy interaction. The efficiency of compressed air energy transfer is defined based on the second law of thermodynamics. A high fidelity model is developed using commercially available software (GT-POWER) to capture the effects of engine friction, heat transfer, gas dynamics, etc. Engine valve timing for optimal efficiency in air regeneration and the corresponding engine speed-torque maps are established using the detailed engine model. The compressed air hybrid engine maps are then incorporated into vehicle simulation (ADVISOR) to evaluate the potential fuel economy improvement for a refuse truck under a variety of driving cycles. Depending on the particular driving cycle, the simulation has shown a potential 4–18% fuel economy improvement over the truck equipped with the conventional baseline diesel engine.

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